Employing CAN in distributed real-time control applications sometimes critically requires increasing the size of distributed area, and communication with both other LANs and independent CAN segments. An interworking device with wireless support to extend CAN segments, utilizing an IEEE 802.11b WLAN is a practical solution for such an industrial environment. A key objective of this research work is to design and implement an interworking device called Wireless Interworking Unit (WIU) enabling remote CAN2.0A nodes to communicate over IEEE 802.11b WLAN using encapsulation method. Computer modeling and simulations of the proposed WIU are carried out using OPNET Modeler. The SAE Benchmark has been utilized in the networking models to evaluate the simulation results obtained. Considering the total end-to-end delay results of especially remote CAN messages for above 40 kbit/s bus rates, effect of the designed WIU is proved not causing to exceed the required arrival time deadline set by the SAE Benchmark. (C) 2007 Elsevier B.V. All rights reserved.